Laser projector systems have been used to assist in various construction techniques, such as the assembly of trusses for building purposes, as well as use in the aircraft manufacturing industry for more precise assembly of certain aircraft components, especially those where extremely narrow tolerances are required.
DPSS is an abbreviation for diode pumped solid state and is used for the technology of producing laser light from solid crystalline material as the lasing medium that is optically pumped from laser diode. Laser diodes produce infrared light of a specific wavelength and it is aligned into the pumped crystal that is capable of lasing a higher wavelength light into a “doubler” crystal that then doubles the frequency and generates visible light of a desired wavelength. Neodymium-doped yttrium aluminum garnet (“Nd:YAG”) and neodymium-doped yttrium orthovanadate (“Nd:YVO4”) are the most popular pumped crystals for low to medium power 1,064 nm and frequency doubled 532 nm (green) diode pumped solid state lasers. Newer technology bonded the two crystals together in an efficient way and eliminated optical alignment and some other disadvantages of the original technology.
The DPM (Diode-Pumped Microchip) laser crystal is a combination of a pumped crystal (denoted as S1) and a frequency doubler (denoted as S2) (e.g., non-linear optical (“NLO”) crystals like potassium titanyl phosphate (“KTP”) bonded together in a chip or microchip, as shown in FIG. 1. For example, the two crystals are polished and bonded together, coated and diced so it is possible to produce a couple of hundred of laser chip crystals from one wafer. Optical alignment is simplified because there is no need for a cavity alignment. These are manufactured in a mass production. Laser modules based on the DPM chip are relatively cost efficient, small in size and make them a perfect candidate for a multi head collimator in a laser projection application.
There are different color DPSS lasers available based on this technology using various crystals. Some of the most popular systems used in the marketplace today are the so-called “green” laser systems, which are referred to by this name due to the color of light emitted therefrom. There are, however, several problems associated with conventional diode pumped solid state lasers, including but not limited to lack of efficiency and low to medium inconsistent power levels.
Furthermore, conventional diode pumped solid state lasers typically require a requisite energy build-up for the crystal. That is, there is typically a relatively high blast of energy directed towards the crystal upon start-up, e.g., full power for about 3 milliseconds or more. These particular problems also manifest themselves in various ways, including inconsistent or unacceptable laser pattern projection, especially during the initial start-up phase of the laser projector system.
Additionally, problems regarding the servicing or replacing the one or more of the laser projector modules is also a concern. Typically, the entire laser projector system, including all of the individual laser projector modules, must be powered down before any one laser projector module can be serviced or replaced. Additionally, convention laser projector systems may need to be at least partially dismantled to access and/or remove any particular laser projector module, which can be a time-consuming and complex operation. These delays cause significant manufacturing delays and add to overall manufacturing costs. Additionally, the laser projector modules of conventional diode pumped solid state lasers can cost approximately $1200-2000, thus making them relatively expensive to replace should they become damaged or otherwise inoperable.
Thus, it would be desirable to have a new and improved laser projector system which overcomes at least one of the aforementioned problems.